Dear Sir/ Madam

No apologies needed. ;)

Thank you for your response, view and suggestion.

Then I guess I would give them credit at the end of the documentary besides Prelinger.

Many thanks for your clear direction.

Apologize for the delay.

I don't own a copyright of this, Stanford Online Archive does. However, I don't think some hard consequences woul follow if use of 20 sec of this *educational* material would happen.

I have more of it contact me at mail[at]aleksas.ru if you need it, they all grabbed from Stanford Bucky Archive which is available at their sight for streaming only. And they ultimately, I think own the copyright for it.